EFFECTS OF PREPARATION PROCEDURES OF CALCIUM-LEAD HYDROXYAPATITES ON THERMAL STABILITIES AND CATALYTIC ACTIVITIES FOR OXIDATIVE COUPLING OF METHANE

Abstract

Binary hydroxyapatite, calcium-lead hydroxyapatite, was prepared by three different procedures; (A) the reaction with calcium and lead acetates with disodium hydrogenphosphate, (B) the surface-treatment of calcium hydroxyapatite with aqueous lead cation, and (C) kneading of the component hydroxyapatites. It was revealed that the thermal stability, the nature of the phosphate groups and the catalytic activities for the oxidative coupling of methane of the binary hydroxyapatite were strongly dependent on the preparation procedures.